1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2018-2019 NXP. 4 */ 5 6 #include <linux/arm-smccc.h> 7 #include <linux/firmware/imx/sci.h> 8 #include <linux/io.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/moduleparam.h> 12 #include <linux/of.h> 13 #include <linux/platform_device.h> 14 #include <linux/watchdog.h> 15 16 #define DEFAULT_TIMEOUT 60 17 /* 18 * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms 19 * in theory, but for normal case, 1s~128s is enough, you can change this max 20 * value in case it's not enough. 21 */ 22 #define MAX_TIMEOUT 128 23 24 #define IMX_SIP_TIMER 0xC2000002 25 #define IMX_SIP_TIMER_START_WDOG 0x01 26 #define IMX_SIP_TIMER_STOP_WDOG 0x02 27 #define IMX_SIP_TIMER_SET_WDOG_ACT 0x03 28 #define IMX_SIP_TIMER_PING_WDOG 0x04 29 #define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05 30 #define IMX_SIP_TIMER_GET_WDOG_STAT 0x06 31 #define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07 32 33 #define SC_TIMER_WDOG_ACTION_PARTITION 0 34 35 #define SC_IRQ_WDOG 1 36 #define SC_IRQ_GROUP_WDOG 1 37 #define SC_TIMER_ERR_BUSY 10 38 39 static bool nowayout = WATCHDOG_NOWAYOUT; 40 module_param(nowayout, bool, 0000); 41 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 42 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 43 44 struct imx_sc_wdt_device { 45 struct watchdog_device wdd; 46 struct notifier_block wdt_notifier; 47 }; 48 49 static int imx_sc_wdt_ping(struct watchdog_device *wdog) 50 { 51 struct arm_smccc_res res; 52 53 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, 54 0, 0, 0, 0, 0, 0, &res); 55 56 return 0; 57 } 58 59 static int imx_sc_wdt_start(struct watchdog_device *wdog) 60 { 61 struct arm_smccc_res res; 62 63 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, 64 0, 0, 0, 0, 0, 0, &res); 65 66 /* Ignore if already enabled(SC_TIMER_ERR_BUSY) */ 67 if (res.a0 && res.a0 != SC_TIMER_ERR_BUSY) 68 return -EACCES; 69 70 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, 71 SC_TIMER_WDOG_ACTION_PARTITION, 72 0, 0, 0, 0, 0, &res); 73 return res.a0 ? -EACCES : 0; 74 } 75 76 static int imx_sc_wdt_stop(struct watchdog_device *wdog) 77 { 78 struct arm_smccc_res res; 79 80 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, 81 0, 0, 0, 0, 0, 0, &res); 82 83 return res.a0 ? -EACCES : 0; 84 } 85 86 static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, 87 unsigned int timeout) 88 { 89 struct arm_smccc_res res; 90 91 wdog->timeout = timeout; 92 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, 93 timeout * 1000, 0, 0, 0, 0, 0, &res); 94 95 return res.a0 ? -EACCES : 0; 96 } 97 98 static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog, 99 unsigned int pretimeout) 100 { 101 struct arm_smccc_res res; 102 103 /* 104 * SCU firmware calculates pretimeout based on current time 105 * stamp instead of watchdog timeout stamp, need to convert 106 * the pretimeout to SCU firmware's timeout value. 107 */ 108 arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG, 109 (wdog->timeout - pretimeout) * 1000, 0, 0, 0, 110 0, 0, &res); 111 if (res.a0) 112 return -EACCES; 113 114 wdog->pretimeout = pretimeout; 115 116 return 0; 117 } 118 119 static int imx_sc_wdt_notify(struct notifier_block *nb, 120 unsigned long event, void *group) 121 { 122 struct imx_sc_wdt_device *imx_sc_wdd = 123 container_of(nb, 124 struct imx_sc_wdt_device, 125 wdt_notifier); 126 127 if (event & SC_IRQ_WDOG && 128 *(u8 *)group == SC_IRQ_GROUP_WDOG) 129 watchdog_notify_pretimeout(&imx_sc_wdd->wdd); 130 131 return 0; 132 } 133 134 static void imx_sc_wdt_action(void *data) 135 { 136 struct notifier_block *wdt_notifier = data; 137 138 imx_scu_irq_unregister_notifier(wdt_notifier); 139 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 140 SC_IRQ_WDOG, 141 false); 142 } 143 144 static const struct watchdog_ops imx_sc_wdt_ops = { 145 .owner = THIS_MODULE, 146 .start = imx_sc_wdt_start, 147 .stop = imx_sc_wdt_stop, 148 .ping = imx_sc_wdt_ping, 149 .set_timeout = imx_sc_wdt_set_timeout, 150 .set_pretimeout = imx_sc_wdt_set_pretimeout, 151 }; 152 153 static struct watchdog_info imx_sc_wdt_info = { 154 .identity = "i.MX SC watchdog timer", 155 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | 156 WDIOF_MAGICCLOSE, 157 }; 158 159 static int imx_sc_wdt_probe(struct platform_device *pdev) 160 { 161 struct imx_sc_wdt_device *imx_sc_wdd; 162 struct watchdog_device *wdog; 163 struct device *dev = &pdev->dev; 164 int ret; 165 166 imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL); 167 if (!imx_sc_wdd) 168 return -ENOMEM; 169 170 platform_set_drvdata(pdev, imx_sc_wdd); 171 172 wdog = &imx_sc_wdd->wdd; 173 wdog->info = &imx_sc_wdt_info; 174 wdog->ops = &imx_sc_wdt_ops; 175 wdog->min_timeout = 1; 176 wdog->max_timeout = MAX_TIMEOUT; 177 wdog->parent = dev; 178 wdog->timeout = DEFAULT_TIMEOUT; 179 180 watchdog_init_timeout(wdog, 0, dev); 181 182 ret = imx_sc_wdt_set_timeout(wdog, wdog->timeout); 183 if (ret) 184 return ret; 185 186 watchdog_stop_on_reboot(wdog); 187 watchdog_stop_on_unregister(wdog); 188 189 ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 190 SC_IRQ_WDOG, 191 true); 192 if (ret) { 193 dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n"); 194 goto register_device; 195 } 196 197 imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify; 198 ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier); 199 if (ret) { 200 imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG, 201 SC_IRQ_WDOG, 202 false); 203 dev_warn(dev, 204 "Register irq notifier failed, pretimeout NOT supported\n"); 205 goto register_device; 206 } 207 208 ret = devm_add_action_or_reset(dev, imx_sc_wdt_action, 209 &imx_sc_wdd->wdt_notifier); 210 if (!ret) 211 imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT; 212 else 213 dev_warn(dev, "Add action failed, pretimeout NOT supported\n"); 214 215 register_device: 216 return devm_watchdog_register_device(dev, wdog); 217 } 218 219 static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) 220 { 221 struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); 222 223 if (watchdog_active(&imx_sc_wdd->wdd)) 224 imx_sc_wdt_stop(&imx_sc_wdd->wdd); 225 226 return 0; 227 } 228 229 static int __maybe_unused imx_sc_wdt_resume(struct device *dev) 230 { 231 struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev); 232 233 if (watchdog_active(&imx_sc_wdd->wdd)) 234 imx_sc_wdt_start(&imx_sc_wdd->wdd); 235 236 return 0; 237 } 238 239 static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops, 240 imx_sc_wdt_suspend, imx_sc_wdt_resume); 241 242 static const struct of_device_id imx_sc_wdt_dt_ids[] = { 243 { .compatible = "fsl,imx-sc-wdt", }, 244 { /* sentinel */ } 245 }; 246 MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); 247 248 static struct platform_driver imx_sc_wdt_driver = { 249 .probe = imx_sc_wdt_probe, 250 .driver = { 251 .name = "imx-sc-wdt", 252 .of_match_table = imx_sc_wdt_dt_ids, 253 .pm = &imx_sc_wdt_pm_ops, 254 }, 255 }; 256 module_platform_driver(imx_sc_wdt_driver); 257 258 MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>"); 259 MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); 260 MODULE_LICENSE("GPL v2"); 261